1. Field of the Invention
The present invention relates to a punching apparatus which punches a hole at a predetermined location by means of a punch and a die.
2. Background Art
There is a type of punching apparatus, in which the punch and the die are in the form of non-circular (for example, quadrangle) cross-section.
Conventionally, the problem has been encountered that since the conventional punching apparatus is constructed such that the punch and the die are permanently arranged (static setting) at predetermined locations, a work or an item to be punched must be set so as to coincide with the setting condition of the punch and the die.
Now, sometimes it becomes necessary to rotate the work when setting the work so as to coincide with the setting conditions of the punch and the die. In some cases, however, it becomes impossible to punch a non-circular hole, since the rotation range of the work is restricted.
It is therefore an objective of the present invention to provide a punching apparatus capable of punching a hole by means of a punch and a die both having non-circular cross-sections.
According to the first aspect of the present invention, in a punching apparatus for punching a hole having a non-circular cross section at a predetermined location on a work by means of a punch and a die, the punch and the die are constituted such that the punch is rotatable relative to the punch supporting portion about the central axis line of the punching direction and fixable at a rotational position around the central axis line of punching direction; and, similar to said punch, said die is rotatable about the central axis line of the punching direction with the same rotational phase as that of said punch, and is fixable at a rotational position around the central axis line of the punching direction.
The above described punching apparatus is constituted such that a supporting portion of said work is movable in two horizontal directions in a plane which crosses the punching direction at an approximately right angle and is swingable about a base point; a connecting means is provided for integrally connecting said punch and said die in order to rotate both said punch and said die at an identical rotational phase; and it is also possible to adopt an detachable connecting means for integrally connecting said punch and said die in order to rotate both said punch and said die at an identical rotational phase.